Original papers: Does strabismus surgery induce significant changes of corneal topography?

Refractive Changes Induced by Strabismus Corrective Surgery in Adults

Purpose. To investigate refractive changes after strabismus correction procedures among adults. Methods. Retrospective chart review of adult patients who had horizontal recti muscles surgery with preoperative and postoperative cycloplegic refraction measurements. The preoperative refraction was mathematically subtracted from the postoperative refraction, and the induced refractive changes were statistically analyzed. Vector analysis was used to examine the magnitude of the toric change. The proportion of clinically significant refractive change was evaluated as well. Results. Thirty-one eyes from 22 subjects met the criteria and were included in the final analysis. A significant postoperative refractive change of the spherical equivalent towards myopia and a change of the astigmatism in the with-the-rule direction were observed. In a subset of 9 cases a third cycloplegic refraction measurement demonstrated stable refraction compared to the 1-month postoperative measurement. In 10 cases of single eye surgery, significant refractive changes were observed only in the operated side when compared to the sound eye. The induced surgical refractive change was of clinical significance (≥0.5 D) in 11 eyes of 9 patients (40.9% of patients). Conclusions. Refractive changes are a significant side effect of horizontal strabismus corrective surgery among adults. Therefore, patients should be informed about it prior to surgery and should be rerefracted in the postoperative period.

Surgically induced astigmatism following medial rectus recession: short-term and long-term outcomes

PURPOSE

The current study aimed to investigate short- and long-term postoperative ocular refractive effects of medial rectus recession on the involved eye and to describe the detectable effects in detail by the results of vector analysis.

METHODS

Data of patients in whom medial rectus recession was performed between 2010 and 2012 were retrospectively evaluated. The study included 52 eyes of 32 patients. Patients with a history of previous ocular surgery, congenital or progressive corneal disease, familial or acquired posterior segment disease, glaucoma, a history of ocular trauma, or any neurological or systemic disease were excluded. Best-corrected and uncorrected visual acuities and refraction examination findings of the patients were recorded before the surgery and at the postoperative first month and first year. A vector analysis program was used to analyze surgically induced astigmatism.

RESULTS

Significant myopic shift and astigmatic change were determined in the spherical equivalent refraction in the early postoperative period (first month); however, these changes disappeared in the long term (at the postoperative first year). A positive correlation was not observed between the amount of surgical recession and the results of ophthalmic examination at the postoperative first month and first year.

CONCLUSIONS

Only postoperative first month spherical equivalent showed a positive correlation with the amount of surgical recession; however, this correlation disappeared at the postoperative first year.